Hello and welcome to another issue of This Week in Rust! Rust is a programming language empowering everyone to build reliable and efficient software. This is a weekly summary of its progress and community. Want something mentioned? Tag us at @ThisWeekInRust on Twitter or @ThisWeekinRust on mastodon.social, or send us a pull request. Want to get involved? We love contributions.

This Week in Rust is openly developed on GitHub and archives can be viewed at this-week-in-rust.org. If you find any errors in this week's issue, please submit a PR.

Updates from Rust Community

Project/Tooling Updates

• This month in Servo: gamepad support, font fallback, Space Jam, and more!
• Announcing Jco 1.0
• This month in Pavex, #9
• argmin 0.10.0 - a Rust crate for numerical optimization

Observations/Thoughts

• Text labels rendering on a map with Rust - research and design
• Rust developers fear language is getting too complex and prefer bug fixes to new features
• Lessons learnt from building a distributed system in Rust
• How Rust Could Change Robotics
• Asynchronous clean-up
• Edge IoT with Rust on ESP: Ping!
• ESP Embedded Rust: Command Line Interface
• ESP Embedded Rust: Ping CLI App Part 2
• Convert a String to int in Rust
• Mastering ManuallyDrop<T> - A Guide to Explicit Resource Management in Rust
• Rust, but async

Rust Walkthroughs

• Matching and iterators in Rust
• Practical guide to Error Handling in Rust
• Building an Async Runtime with mio
• [HE] [video] Rust Course

Miscellaneous

• Guide to using TensorFlow in Rust
• A Twist on Wadler's Printer
• Implementing API Rate Limiting in Rust
• How to benchmark Rust code with Iai
• How Rust Could Change Robotics
• Sequential-storage: efficiently store data in flash
• [audio] Sentry - Rust in Production Podcast
• [video] A First Look at Lifetimes in Rust
• [video] Firmware for an ESP32 to read from a noise sensor in Rust

Crate of the Week

This week's crate is web-audio-api-rs, a Rust implementation of the Web Audio API for use outside the browser.

Thanks to Otto Rottier for the self-suggestion!

Please submit your suggestions and votes for next week!

Call for Testing

An important step for RFC implementation is for people to experiment with the implementation and give feedback, especially before stabilization. The following RFCs would benefit from user testing before moving forward:

• No RFCs issued a call for testing this week.

If you are a feature implementer and would like your RFC to appear on the above list, add the new call-for-testing label to your RFC along with a comment providing testing instructions and/or guidance on which aspect(s) of the feature need testing.

Call for Participation; projects and speakers

CFP - Projects

Always wanted to contribute to open-source projects but did not know where to start? Every week we highlight some tasks from the Rust community for you to pick and get started!

Some of these tasks may also have mentors available, visit the task page for more information.

• Hyperswitch - [FEATURE] : add offset field to disputes list
• Hyperswitch - [FEATURE]: addoffset field to mandates list
• Ockam - ockam node create --identity X should fail if X doesn't exist
• Ockam - Output for ockam project ticket is improved and information is not opaque
• Ockam - Output for both ockam project ticket and ockam project enroll is improved, with support for --output json
• ZeroCopy - In zerocopy-derive UI tests, detect whether we're building with RUSTFLAGS='-Wwarnings'

If you are a Rust project owner and are looking for contributors, please submit tasks here.

CFP - Speakers

Are you a new or experienced speaker looking for a place to share something cool? This section highlights events that are being planned and are accepting submissions to join their event as a speaker.

If you are an event organizer hoping to expand the reach of your event, please submit a link to the submission website through a PR to TWiR.

Updates from the Rust Project

430 pull requests were merged in the last week

• Avoid non-local definitions in functions (RFC #3373)
• wasm: store rlib metadata in wasm object files
• account for RPITIT in E0310 explicit lifetime constraint suggestion
• actually use the right closure kind when checking async Fn goals
• add #[rustc_no_mir_inline] for standard library UB checks
• allow for a missing adt_def in NamePrivacyVisitor
• avoid generalization inside of aliases
• by changing some attributes to only_local, reducing encoding attributes in the crate metadate
• do not const prop unions
• don't ICE on anonymous struct in enum variant
• expand weak alias types before collecting constrained/referenced late bound regions + refactorings
• fix panic when compiling Rocket
• make intrinsic fallback bodies cross-crate inlineable
• make it possible for outside crates to inspect a mir::ConstValue with the interpreter
• make non-PartialEq-typed consts as patterns a hard error
• mark min_exhaustive_patterns as complete
• match lowering: Introduce a TestCase enum to replace most matching on PatKind
• match lowering: eagerly simplify match pairs
• match lowering: simplify empty candidate selection
• match lowering: test one or pattern at a time
• Fix liveness analysis in the presence of never patterns
• no need to validate_alias_bound_self_from_param_env in assemble_alias_bound_candidates
• prevent cycle in implied predicates computation
• promotion: don't promote int::MIN / -1
• properly emit expected ; on #[attr] expr
• provide suggestions through rustc_confusables annotations
• refactor trait implementations in core::convert::num
• split Diagnostics for Uncommon Codepoints: Add Individual Identifier Types
• support async trait bounds in macros
• unify dylib loading between proc macros and codegen backends
• when encountering <&T as Clone>::clone(x) because T: Clone, suggest #[derive(Clone)]
• miri: /miri many-seeds: support MIRI_SEED_END to control the end of the seed range
• miri: add "cargo miri clean" command
• miri: windows miri-script execution ergonomics
• use br instead of a conditional when switching on a constant boolean
• stabilize cfg_target_abi
• improve UEFI stdio
• windows: use ProcessPrng for random keys
• require simd_insert, simd_extract indices to be constants
• make Barrier::new() const
• implement MappedMutexGuard, MappedRwLockReadGuard, and MappedRwLockWriteGuard
• add "algebraic" fast-math intrinsics, based on fast-math ops that cannot return poison
• remove useless 'static bounds on Box allocator
• mpsc: fix race between block initialization and receiver disconnection
• futures: add 'static bound to waker_ref
• cargo add: Improve error when adding registry packages while vendored
• cargo: Control clap colors through config
• cargo: Respect CARGO_TERM_COLOR in '--list' and '-Zhelp'
• cargo: error messages when collecting workspace members now mention the workspace root location
• cargo: support target.<triple>.rustdocflags officially
• rustdoc: include crate name in links for local primitives
• clippy: box_default: preserve required path segments
• clippy: read_line_without_trim: detect string literal comparison and .ends_with() calls
• clippy: add unnecessary_clippy_cfg lint
• clippy: add new multiple_bound_locations lint
• clippy: add new unnecessary_get_then_check lint
• clippy: allow unused_imports, and unused_import_braces on use
• clippy: don't lint infinite_loop in external or proc macros
• clippy: make redundant_guards take constness into account
• clippy: unused_unit: be careful with expressions with attributes
• clippy: new lint: empty docs
• clippy: extend unnecessary_to_owned to handle Borrow trait in map types
• clippy: fix sign-handling bugs and false negatives in cast_sign_loss
• clippy: fix suggestion error in useless_vec
• clippy: fix no_effect_underscore_binding firing on ignored parameters of async fns
• clippy: look for implied_bounds_in_impls in more positions
• clippy: take lifetime extension into account in ref_as_ptr
• rust-analyzer: add assist for filling fields by replacing ellipsis in record syntax
• rust-analyzer: add short flag -V for consistency with other rust tooling
• rust-analyzer: add "make tuple" tactic to term search
• rust-analyzer: replace_filter_map_next_with_find_map shouldn't work for dyn trait
• rust-analyzer: don't panic on synthetic syntax in inference diagnostics
• rust-analyzer: fix completions panicking with certain macro setups
• rust-analyzer: fix deadlock in recreate_crate_graph <-> file_line_index
• rust-analyzer: fix modules in blocks not resolving in ide layer
• rust-analyzer: fix proc-macro server not accounting for string delimiters correctly
• rust-analyzer: fix recompiles due to RUSTC_BOOTSTRAP
• rust-analyzer: panic when inlining callsites inside macros' parameters
• rust-analyzer: merge BorrowKind::Unique into BorrowKind::Mut
• rust-analyzer: speed up Method Completions By Taking Advantage of Orphan Rules

Rust Compiler Performance Triage

A rare week where regressions out powered improvements to make the compiler roughly half a percent slower on average on nearly 100 benchmarks. Some regressions have fixes in the pipeline, but some remain elusive or were introduced to address correctness issues.

Triage done by @rylev. Revision range: 5af21304..71ffdf7f

Summary:

4 Regressions, 6 Improvements, 5 Mixed; 2 of them in rollups 58 artifact comparisons made in total

Full report here

Approved RFCs

Changes to Rust follow the Rust RFC (request for comments) process. These are the RFCs that were approved for implementation this week:

• No RFCs were approved this week.

Final Comment Period

Every week, the team announces the 'final comment period' for RFCs and key PRs which are reaching a decision. Express your opinions now.

RFCs

• No RFCs entered Final Comment Period this week.

Tracking Issues & PRs

Rust

• [disposition: merge] Lint singleton gaps after exclusive ranges
• [disposition: merge] Tracking Issue for slice::split_at_unchecked() and split_at_mut_unchecked()
• [disposition: merge] Tracking Issue for generic NonZero
• [disposition: merge] Made INVALID_DOC_ATTRIBUTES lint deny by default
• [disposition: merge] Tracking Issue for ARM CRC32 intrinsics
• [disposition: merge] use confstr(_CS_DARWIN_USER_TEMP_DIR, ...) as a TMPDIR fallback on Darwin

New and Updated RFCs

• [new] RFC: RArrow Dereference for Pointer Ergonomics

Upcoming Events

Rusty Events between 2024-02-28 - 2024-03-27 🦀

Virtual

• 2024-02-29 | Virtual (Berlin, DE) | OpenTechSchool Berlin + Rust Berlin
  • Rust Hack and Learn | Mirror: Rust Hack n Learn Meetup | Mirror: Berline.rs page
• 2024-02-29 | Virtual (Charlottesville, NC, US) | Charlottesville Rust Meetup
  • Surfing the Rusty Wireless Waves with the ESP32-C3 Board
• 2024-03-06 | Virtual (Dublin, IE) | Rust Dublin
  • An intro to nom, parsing made easy for Rustaceans
• 2024-03-06 | Virtual (Indianapolis, IN, US) | Indy Rust
  • Indy.rs - with Social Distancing
• 2024-03-07 | Virtual (Charlottesville, NC, US) | Charlottesville Rust Meetup
  • Crafting Interpreters in Rust Collaboratively
• 2024-03-12 | Virtual (Dallas, TX, US) | Dallas Rust
  • Second Tuesday
• 2024-03-12 | Hybrid (Virtual + In-person) Munich, DE | Rust Munich
  • Rust Munich 2024 / 1 - hybrid
• 2024-03-14 | Virtual (Berlin, DE) | OpenTechSchool Berlin
  • Web Frontend Co-Learning (online)
• 2024-03-14 | Virtual (Berlin, DE) | OpenTechSchool Berlin + Rust Berlin
  • Rust Hack and Learn | Mirror: Rust Hack n Learn Meetup | Mirror: Berline.rs page
• 2024-03-14 | Virtual (Nürnberg, DE) | Rust Nüremberg
  • Rust Nürnberg online
• 2024-03-21 | Seattle, WA, US | Seattle Rust User Group
  • Seattle Rust User Group Meetup
• 2024-03-26 | Virtual + In Person (Barcelona, ES) | BcnRust
  • 13th BcnRust Meetup - Stream

Europe

• 2024-02-29 | Berlin, DE | Rust Berlin
  • Rust and Tell - Season start 2024
• 2024-02-29 | Copenhagen, DK | Copenhagen Rust Community
  • Rust Meetup #44 sponsored by Bang & Olufsen
• 2024-03-06 | Zürich, CH | Rust Zürisee
  • How to (partial) Migration - March Meetup
• 2024-03-12 | Munich, DE + Virtual | Rust Munich
  • Rust Munich 2024 / 1 - hybrid
• 2024-03-13 | Paris, FR | Paris Rustaceans
  • Rust Meetup in Paris
• 2024-03-14 | Reading, UK | Reading Rust Workshop
  • Reading Rust Meetup at Browns
• 2024-03-19 | Aarhus, DK | Rust Aarhus
  • Hack Night
• 2024-03-19 | Leipzig, DE | Rust - Modern Systems Programming in Leipzig
  • Rust Interactive Session
• 2024-03-20 | Girona, ES | Rust Girona
  • Introduction to programming Microcontrollers with Rust
• 2024-03-21 | Augsburg, DE | Rust Meetup Augsburg
  • Augsburg Rust Meetup #6
• 2024-03-21 | Lille, FR | Rust Lille
  • Rust Lille #6: Du RSS et de L'ECS !
• 2024-03-26 | Barcelona, ES + Virtual | BcnRust
  • 13th BcnRust Meetup
• 2024-03-26, 2024-03-28 | London, UK | Rust Nation UK
  • Rust Nation 2024

North America

• 2024-02-28 | Austin, TX, US | Rust ATX
  • Rust Lunch - Fareground
• 2024-02-28 | Chicago, IL, US | Deep Dish Rust
  • Rust Happy Hour
• 2024-03-04 | Cambridge, MA, US | Boston Rust Meetup
  • Central Cambridge Rust Lunch
• 2024-03-07 | Mountain View, CA, US | Mountain View Rust Meetup
  • Rust Meetup at Hacker Dojo
• 2024-03-13 | Boston, MA, US | Boston Rust Meetup
  • Northeastern Rust Lunch
• 2024-03-19 | San Francisco, CA, US | San Francisco Rust Study Group
  • Rust Hacking in Person
• 2024-03-27 | Austin, TX, US | Rust ATX
  • Rust Lunch - Fareground
• 2024-03-27 | Hawthorne, CA, US | Freeform
  • Rust in the Physical World 🦀 Tech Talk Event at Freeform

Oceania

• 2024-02-29 | Brisbane, QLD, AU | Rust Brisbane
  • February Meetup
• 2024-03-05 | Auckland, NZ | Rust AKL
  • Rust AKL: Introduction to Embedded Rust + The State of Rust UI

If you are running a Rust event please add it to the calendar to get it mentioned here. Please remember to add a link to the event too. Email the Rust Community Team for access.

Jobs

Please see the latest Who's Hiring thread on r/rust

Quote of the Week

That would take 18 million terabytes of RAM. You don't have that much memory.

– Alice Ryhl answering "What is MAX array size" on rust-users

Thanks to Zeroexcuses for the suggestion!

Please submit quotes and vote for next week!

This Week in Rust is edited by: nellshamrell, llogiq, cdmistman, ericseppanen, extrawurst, andrewpollack, U007D, kolharsam, joelmarcey, mariannegoldin, bennyvasquez.

Email list hosting is sponsored by The Rust Foundation

Discuss on r/rust